The present invention relates to an improved side marker clearance and reflex lamp assembly to be used with recreational vehicles, such as boat trailers. More specifically, the invention relates to a support used to ground a lead wire extending from the lamp to the recreational vehicle.
Replaceable side marker lamps have long been used on many different types of recreational vehicles. A lamp of this type is disclosed in U.S. Pat. No. 5,150,959. The lamps are of simple construction, comprising a plastic base, a lighting mechanism affixed to the base, and a translucent plastic lens hermetically sealed over the base and enclosing the lighting mechanism. The lighting mechanism includes a side marker bulb, received within a seat extending forwardly from the base. The mechanism also includes a bulb conductor strip and a ground conductor strip located in the seat that provide an electric socket for the bulb. The conductor strips extend beneath the seat into a recess located under the seat, and a lead wire is attached to the bulb conductor strip.
To supply electrical power to the lamp, the lead wire extends outwardly from the recess in the base of the lamp and is sealed in connection with the bulb conductor strip by a layer of a thermosetting resin filling the recess in the base. The lead wire is connected to the electrical system of the vehicle through a hole in the exterior of the vehicle.
The ground strip, as disclosed in the aforementioned patent, includes a central plate-like section that protrudes below the base of the lamp and extends parallel to the base, allowing the central section to contact the exterior surface of the recreational vehicle when the lamp is mounted to the vehicle. In this manner, the ground strip electrically contacts the recreational vehicle body and forms a ground for the lighting mechanism contained within the lamp.
In mounting the lamp to the vehicle, as described in the aforementioned patent, the lamp is secured to the exterior of the recreational vehicle body by a pair of screws inserted into and retained within a pair of cylindrical wells in the lamp. The wells extend through the lens and are aligned with openings in the base of the lamp. The screws are inserted into the wells and protrude through the openings in the base of the lamp to engage the exterior surface of the recreational vehicle body. One of the wells is located directly over the central section of the ground conductor strip. Thus, when the screw inserted into that well is engaged with the exterior surface of the recreational vehicle body, the screw pierces the central section and presses it into contact with the vehicle body to form the ground for the lamp.
With certain types of vehicles, in order to vertically position the lamp on the vehicle, it is necessary to place a support for the lamp between the lamp and the vehicle body. In most situations where a support is necessary, the support is wedge-shaped to accommodate an angled, non-horizontal surface on the vehicle body to which the lamp is mounted. The wedge-shaped support vertically positions the lamp, allowing the lamp to face in a horizontal direction, and allowing for proper viewing of signals generated by or reflecting from the lamp.
However, when utilizing a support, the support necessarily separates the central section of the ground conductor strip from the vehicle body, preventing the central section from coming into direct electrical contact with the vehicle. Therefore, the ground conductor strip in the lighting mechanism of the lamp must be connected to the vehicle in some other manner.
To solve this problem, some prior art lamp supports are formed entirely of an electrically conductive material, such as die cast aluminum. Thus, an electrical ground is formed through the contact of the central section with the aluminum support, and the support with the vehicle body. These die cast supports, in order to be aesthetically pleasing while in use, are painted to match the color of the base of the lamp. Also, the supports are attached to the vehicle by welding them directly onto the exterior surface of the recreational vehicle body.
Overall, these prior art supports provide an effective means for creating a ground between the lamp and the vehicle when the lamp is necessarily spaced a distance from the vehicle body. However, as the support is welded to the vehicle body, the body of the recreational vehicle is marred due to the manner in which the support is attached to the vehicle. Furthermore, should the lamp support ever need to be replaced, due to damage to the support, or for other reasons, the support would need to be removed from the vehicle body, further marring the exterior surface of the vehicle body. This damage must be repaired or covered over in order to preserve the aesthetically pleasing appearance of the recreational vehicle.
The method in which these supports are made also illustrates other shortcomings of supports of this type. First, the supports are die cast, making each support relatively expensive and difficult to manufacture. Also, as the supports are painted to match the lamp base, any paint coming between the ground plate and the support can interfere with the electrical grounding connection between the lamp and the support, and possibly, the support and the vehicle.